john vs lav

john and lav both are nouns.

Word	Noun	Adjective	Verb	Adverb
john	Yes	No	No	No
lav	Yes	No	No	No

As nouns, john and lav are synonyms defined as:

Other synonyms of john include bathroom, can, lavatory, privy, toilet.

john (noun)	lav (noun)
a room or building equipped with one or more toilets	a room or building equipped with one or more toilets
a prostitute's customer